The present invention refers to a method of producing colored surfaces on parts of aluminum or aluminum alloy.
Aluminum parts, such as aluminum stampings or rolled sections are used, inter alia, in the hardware and lighting industries or, in particular, also in automobile manufacture, for instance, for window mounting systems or else as ornamental frames, ornamental moldings and the like. In this connection, it is also known to use parts of aluminum or aluminum alloy which have a colored anodized surface.
The object of the present invention is to provide a new method of producing colored surfaces on aluminum or aluminum- alloy parts in which the parts which are colored by this method have the following quality features:
a) 1,000-hour light-fastness testing without fading and without change in the color pigmentation. Testing: Xenotest Hot Light Exposure 450 DIN 75202. PA1 b) 6 cycles Kesternich DIN 50018 Testing for corrosion resistance PA1 c) 5,000 strokes--Testing of fastness to rubbing without change of surface according to Veslick DIN 53339. PA1 gold - bronze PA1 light - dark bronze PA1 gray - brown PA1 gray - blue PA1 anthracite PA1 light - dark blue PA1 blue - violet
The new method is also characterized by the fact that multiplicity of colors with color gradations viz
is made possible on coloring of the parts as well. The new method also allows for a simple verification of the results of the coloring and reproduceability at all times of the individual shades of color.